Users can view images and descriptions of speculative projects ranging from Buckminster Fuller’s dome over midtown Manhattan, to Antonio Gaudi’s unbuilt cathedral, to Archigram’s pop-futurist “Walking City,” all while standing on the projects’ intended sites.

In other words, you go around the city, iPhone in hand – a kind of architectural dowsing rod held in front of you – discovering the traces of buildings that never were (perhaps even fragments of a city yet to come).

Proposals by Buckminster Fuller are suddenly as real as the Empire State Building – after all, they’re both pictured right there on your iPhone…

A mile-high dome shades Midtown Manhattan, an airport floats off Battery Park, Harlem is enveloped in a hulking megastructure literally lifting residents out of poverty, and the tallest building in the world, continuously under construction, sprouts from ground zero, growing without end.

“It’s the city that never was but could have been,” said Irene Cheng, an architectural historian. “Sort of an alternate future.”

Without mining the architectural avant-garde and its history of impossible projects, and before you even get to things like science fiction films and comic books, and as you hold yourself back from exploring the spatial reserves of ancient myth and urban legend – weird tunnels beneath midtown, World War II bunkers, secret apartments of the rich and famous – you can simply tap the ongoing economic recession for architectural content.

You walk past a certain corner on the Upper West Side and your iPhone starts to ring: you’re being called by a missing building… Absent structures detected in a wireless blur, leaving messages for you (complete with call-back number).

On one level, of course, it’s worth asking whether or not it’s a problem that all of these new and exciting visions for 21st-century urban life are only accessible to people rich enough to afford iPhones – but, on another level, why not use the tools that exist, no matter how expensive they might be, in order to try out new models for historical and spatial exploration?

Caving, for instance, requires caving equipment – and not everyone can afford to stock up. But that’s no reason to stop exploring the underworld.

At a conference in Turin earlier this summer, I was on a panel with Bruce Sterling and Nicolas Nova, where Nova asked this exact question. Having just shown us all a series of slides in which new ways of interacting with, and learning about, the city had been suggested, he pointed out that most of these things required an iPhone. But do we really want to build and promote the city of tomorrow, if it’s effectively inaccessible to a particular class of consumers?

Yet, one could argue, this is exactly what we’ve done with cars; the spatial needs of the automobile industry have shaped our cities far more than the cultural and economic – and possibly evenneurological – needs of those cities’ inhabitants.

So will iPhones do to urban information what cars have done to the streetscape?

In any case, back in 2008, in a post that now seems remarkably dated, I suggested that Google Maps should come with a “sci-fi layer” – that is, a layer that would document where in your city certain events had taken place or certain structures had stood in a work of fiction. For instance, the building that Robert Neville’s dog runs into in I Am Legend or the trainyard from Escape From New York, the apartments from Make Room! Make Room!, the high-rise penthouse from The Day After Tomorrow…

Those are Manhattan-centric examples, of course, and drawn only from science fiction, but this could easily be expanded to include landscapes and structures elsewhere, from the deserts of the Empty Quarter to central Paris, and it could include other genres, from the poems of John Ashbery to Howl to The Great Gatsby.

You could even have a “mythology layer” – roaming around Scandinavia, tracking Thor or digging for the roots of Yggdrasil – or a “theology layer”: you go to Israel and your iPhone short-circuits from the laminations of charged geography around it. Pillars of salt, sacred basements, dead walls and abandoned forts.

In fact, I’m further reminded of a project produced this past summer by Sally Hsu, one of my students at Urban Islands down in Sydney. Hsu came up with something she called the Research Institute of Phantomology, a fake historical research society whose specially-invented machines could detect missing buildings: structures that had been demolished and lost to history. You could use these throughout the Sydney Harbor – or specifically on Cockatoo Island, where our studio was set – in order to trace the architectural remains of history.

One of those devices, according to Hsu, was the Architectural Ghost Chaser: it would lead historians directly to the ruins of old buildings in the earth.

A tongue-in-cheek proposal, of course – Hsu even made patent diagrams to illustrate it, as well as a fake cover for New Scientist featuring the remarkable device – it nonetheless kicked-off an interesting conversation about demolished buildings, urban archaeology, and the strategies through which we could detect the ruins of the past if physical excavation is not an option. After all, we’ve already got things like ground-penetrating radar – through which we can map and explore an ancient Roman city beneath Wroxeter, England, without digging a single hole – and we’ve even got muon detectors. But imagine discovering new archaeological sites through an iPhone app!

So why not build a tricked-out PKE Meter attuned to architectural space? At the exact intersection of Sally Hsu’s Institute of Phantomology and the iPhone?

Cheng+Snyder‘s free download opens up a new kind of historical spectating: architectural tourism of the unbuilt. Perhaps someday we’ll be done with monographs, traveling exhibitions, and even senior thesis reviews; we’ll simply upload all our projects into the Phantom City and let the world decide their worth. Crowds of tourists mill about on 13th Street, looking around at the imaginary buttresses of a superstructure you’ve spent three years digitally assembling.

This is a fascinating platform for exploring the latent imaginaries buried under/embedded in/folded into the built environment, capable of mining a precise history of a site through its virtualities rather than/in addition to its actualities. The surfacing of the virtual here washes the city-as the project's title aptly suggests-in the phantasmagoric and uncanny. "Here lies architecture, unbuilt." Would love to see this project extend beyond the city, and, as Geoff suggests, to multiple "exhibition" types/thematics.

now if this sort of alternate/virtual topology could intersect with augmented reality technology, which is availiable on the iphone to a certain extent. to allow the iphone, or similar camera/equipped device, to act as a literal window into an alternate city. So far implementation of augmented reality tech on the iphone has been limited to a "heads up display" mode overlaying mostly textual information, but the potential of overlaying images or three-dimensional content to create complete alternate versions of our environments is clear.

I find it hard to worry about the money an iPhone costs when you can get one for $100. I mean, if you can't talk about and use things that cost $100, we wouldn't be talking much about computers or cars or cordless drills or interior paint. iPhones seem like a luxury object, but really they're not. That's the magic of a gadget.

I have long imagined a world connected to technology that simulates the 'Dynamic Labyrinth' that the Situationists postulated. Where the digital overlay of information in a public space becomes just as important as the space itself. I think devices such as the iPhone and the android platform are slowly getting us there.Going to install this app and see what its like.

I agree with Oliver's reference of Alain Robbe-Grillet's book Tpology of a Phantom City (Topologie d'une ville fantôme) that I will reread after rereading your post. Fascinating!And thanks Oliver for the last reference, I din't know about Project for a Revolution in New York… I'm lazy I will try to find its French version.

"On one level, of course, it's worth asking whether or not it's a problem that all of these new and exciting visions for 21st-century urban life are only accessible to people rich enough to afford iPhone"

This kind of verbal spew is the hall mark of this site. The simple point somehow transgressed is rather …what is the point of a tour such as this anyway? As far as Im concerned, touring 'nothing' is a an superficial excercise verging on ridiculous. And In the face of such a metropolis of living history.

The idea that only the rich can afford iphones as being at all relevant here is just ill considered vacuous tripe, verging on dangerously inerudite.

Anonymous, the mind reels: do you ever read your own comments…? For instance, do you put any thought at all into things like spelling, grammar, punctuation, or even, yes, erudition? Or do you just translate yourself through Babelfish because you think it sounds better to critique other people's writing that way?

I haven't read the Robbe-Grillet book, meanwhile, but I'd love to. I'll look for it this fall or winter. Thanks for the suggestion!

Alexis, I agree, in the end, about the iPhone pricing issue; my point is simply that 1) it's possible that the city of the future, so to speak, will only be accessible to those who can afford certain devices, but that 2) this is no reason not to develop those tools anyway. Thus the reference to caving equipment – i.e. you need the right equipment to pursue any real interest (even walking), and so there's no reason to feel guilty about designing for those platforms.

And, of course, 3) the American city of today is already built only for people who can afford certain devices: private automobiles. Compared to how wrongly over-prioritized the car is in terms of urban space, worries about iPhones and their apps seem misplaced.

Nice post. And one that couldn't be more timely for me. These are the exact ideas I'm styding right now. Actually, the Phantom City rendering is freakishly like a drawing I turned in last week!

Anyway, I think mobile devices and locative media are definitely changing the "user experience" of a city. We can't get lost in a city (at least until new criminals start hacking our turn-by-turn GPS navigators to lead us down dark alleys). Invisible histories are suddenly available. The "artifacts" written about by Aldo Rossi in Architecture and The City are revealed on google maps through embedded images and wikipedia entries. As other commenters have noted, data and information can be given urban form, albeit viewable only through the mediation of "augmented reality" apps, a whole new context emerges to which architects can begin to respond.

And to which advertisers will probably respond as well. Culling info from your emails, texts, and facebook updates, its easy to imagine that Phantom City might occasionally be interrupted with a virtual billboard for Pepsi.

> Jimmy Stamp"Anyway, I think mobile devices and locative media are definitely changing the "user experience" of a city. We can't get lost in a city (at least until new criminals start hacking our turn-by-turn GPS navigators to lead us down dark alleys)" I agree with you. Let's take a simple example. In Paris where I partly live, we have to do with transports (subway, or métro in French, also train such as francilien and RER) that are frequently facing with incidents (technical, human) and of course so-called strike. Before getting your subway you can check with your phone or something else with gps or locative medias or whatever if your subway or train functions. I commute everyday between my town (a quiet small town near Paris) to Paris. I tested it several weeks ago because a "suicide" blocked my line. Checking my iPhone — I have an iPhone so I take this example, but now many mobiles (BlackBerry, Phones with Android system, and maybe Windows mobile, but I can't confirm it) permit to inform us of what's happening in our city thanks to applications —, I was able to reorganize and take another line quickly (or in real time) while before I confess we, users, were always furious because we couldn't get quickly informations on our line.> all of youBut I agree with this remark: "On one level, of course, it's worth asking whether or not it's a problem that all of these new and exciting visions for 21st-century urban life are only accessible to people rich enough to afford iPhone" it is relevant that this will be an unbalanced system,that is, those who can afford those exciting mobiles and those who can't. There is a book written by Saskia Sassen. In French it has been translated and launched this year in the title "La globalisation. Une sociologie", I suppose that in English it was several years ago, I don't know but the title is Sociology of Globalisation" (actually she published it in 2007 in America). I attended a conference in Paris, last May, on the relation between information and cities with her participation, that of Eyal Weizman, Stephen Graham, etc. I remember that she argued that new technologies have produced an unbalanced system, as I mentioned above, that is those who can afford new technologies (Internet, GPS, etc) and those can't afford and/or don't want to. She said that the last group will be considered as "marginal group", that is, this group is not "adaptable to" the changes of lifestyle, if not to say cities in the global era (this is what she said, if I remember). I was surprised, but to a certain extent, if not to say to a large extent, she was and I mean she is right. and Geoff Manaugh's thread illustrates perfectly what she said. I hope I was clear. Have a nice Sunday.

Considering you need to also buy a $30/mo data plan, a minimum $40/mo phone plan, and for this app I'm assuming also the $10/mo GPS feature for 24 months, the $100 iphone ends up being over $2000, which, while less than a car… is still a lot for a psychogeographic prosthetic. Not to suggest that it is somehow unethical to develop these toys, but it's kind of irritating the way iphone stands for all smartphones because it has the most polished interface. Wouldn't it be more compelling to promote urban interaction applications across the whole spectrum: from the dumbest mobile to the most intelligent smart phone?

(written as one who wants (but can't afford) an iphone, would like to run android on it, and is more than content with a zipcar)

I immediately thought of an old MIT Press book, Unbuilt America, which was complete with the 19th century Proposal for the Aggrandizement of Washington DC.

When I first saw one of those computer driven overhead projector gadgets, my first thought was to turn it into an informational Claude glass. With a GPS and positional tracking it could have provided overlays on reality. The iPhone is a lot cheaper, and it's here.

Super article and good to hear that augmented reality is taking off. What is important to remember is that is should never be meant as an alternative to reality but rather a supplement. Where education and knowledge meet the fantastic. For those interested keep a look out for the application that the Netherlands Architecture Institute will be launching the end of this year: and augmented reality view Rotterdam and eventually all of the Netherlands. Just like wished for in the comments, a window to models, images, videos and text of buildings of the past, present and future.

> Huib HayeGood comment.I will add for you sentence "Where education and knowledge meet the fantastic." and the virtual. This is what fascinates me… More and more research work this topic, such French Think Tank Chronos.I would like to thank you for letting us know about this:"For those interested keep a look out for the application that the Netherlands Architecture Institute will be launching the end of this year: and augmented reality view Rotterdam and eventually all of the Netherlands." It, indeed, sounds exciting.I will regularly check in order to have more information on this application.